PSI - Issue 44

Fabio Di Trapani et al. / Procedia Structural Integrity 44 (2023) 496–503 Di Trapani et al./ Structural Integrity Procedia 00 (2022) 000–000

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5. Conclusions Evaluation of the additional shear demand in RC frame members due to the interaction with the infills is decisive in the assessment of seismic performance of reinforced concrete building subject to earthquake loads. The paper presented a numerical investigation on six infilled frame specimens subject to in plane loads. A refined micromodel realized with OpenSees / STKO, was used to determine the additional shear demand at the end of the columns of these specimens. Subsequently, an analytical formulation was proposed to estimate the additional shear demand using the quite simple and popular equivalent strut approach. Results have shown that the additional shear demand can be related to the current axial force acting on the equivalent strut, and also depend on the effective contact length of the infill with the frame ( α l ). Preliminary comparisons of the shear demand estimated with the micromodel with that of the micromodel provided quite good results assuming contact length values in the range 0.25 l - 0.40 l . The proposed model allows performing real time shear safety checks at the end of the columns, maintaining all the advantages of using the equivalent strut approach to analyzed infilled frames. More research is needed to validate the proposed model against a larger dataset of experimental tests and also to provide timely values for the contact lengths having general validity. Acknowledgements This paper was supported by DPC-ReLuis 2022–2022, WP10, Subtask 10.1.2 - Non-structural masonry. References Bergami, A.V., Nuti, C., 2015. Experimental tests and global modeling of masonry infilled frames. Earth Struct 9(2), 281–303. Caliò, I., Pantò, B., 2014. A macro-element modelling approach of Infilled Frame Structures. Comput Struct 143, 91–107. Cavaleri, L., Di Trapani, F., 2014. 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